Donald Trump is not a man known for his finely tuned diplomatic instincts. He insists that he has great relationships with most world leaders and that he possesses preternatural negotiating skills, but the former claim is repeatedly refuted by statements by the leaders themselves and the latter is demonstrably nothing more than reality television fabrication.

A new report from The Washington Post has emerged that shows just how ludicrous the dual Trump claims actually are. During a phone call in June with Japanese Prime Minister Shinzō Abe in which the two heads of state discussed trade and North Korea, Trump strangely brought up the World War II attacks on Pearl Harbor.

“I remember Pearl Harbor,” the President of the United States said, even though he had not yet been born when the infamous surprise attack was carried out. He was born over four years later.

It also bears mentioning that the current Japanese government is not the same as the Empire of Japan which attacked the American naval base in Hawaii on December 7th, 1941. Trump’s comments make absolutely no sense in terms of contemporary geopolitics and underscore just how little he actually understands the world he has been tasked with running.

Trump then went on to complain about Japanese economic policies. He asked for a bilateral trade deal with Japan, an unlikely prospect given the fact that Trump himself torpedoed America’s involvement in the Trans-Pacific Partnership, a trade deal that would have strengthened economic ties with not only Japan but numerous Pacific Rim countries. The Post reports that the conversation left Abe “exasperated.”

The details of this conversation, like so many others between Trump and world leaders, are deeply embarrassing. Every time he opens his mouth the United States’ reputation slides a little further into the gutter. He has no idea what he’s talking about, and his childish attempts at diplomacy are wreaking damage that will take decades to undo.